Once the weather is cooling off, you are probably wondering about how you’ll make the most of your heating and cooling. After all, HVAC costs routinely make up a significant chunk of your monthly electric bill. To learn new ways to save, some owners look closer at their thermostat. Is there a setting they should use to improve efficiency?

The bulk of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a regular cycle, what will the fan setting provide for your HVAC system? This guide will help. We’ll review what exactly the fan setting is and how you can use it to cut costs during the summer or winter.

Should I Use My Thermostat's Fan Setting?

For most thermostats, the fan setting signifies that the air handler’s blower fan stays on. A few furnaces can run at a low level with this setting, but for the most part heating or cooling isn’t being made. The ‘Auto’ setting, on the other hand, will run the fan through a heating or cooling cycle and turn it off after the cycle is over.

There are advantages and disadvantages to switching on the fan setting on your thermostat, and what's ideal {will|can|should]] depend on your distinct comfort needs.

Advantages to using the Fan/On setting:

  • You can keep the temperature in every room more consistent by permitting the fan to keep generating airflow.
  • Indoor air quality can increase since continuous airflow will keep passing airborne pollutants through the air filter.
  • A smaller number of start-stop cycles for the blower fan helps extend its life span. Because the air handler is usually connected to the furnace, this means you can avoid needing furnace repair.

Downsides to using the Fan/On setting:

  • A continuous fan will likely add to your energy expenses somewhat.
  • Continuous airflow may clog your air filter soon, increasing the frequency you will want to replace it.

{Choosing Between|Should My Thermostat Be on|Which Setting for My Thermostat? Fan or Auto in Each Season

In the summer, warm air will sometimes stick around in unfinished spaces like the attic or an attached garage. If you leave the fan on, your HVAC system can gradually move this warm air into the rest of your home, forcing the HVAC system to run longer to preserve the set temperature. In severe heat, this could lead to needing AC repair more often as wear and tear gets worse.

The reverse can take place in the winter. Cooler spaces like a basement will hold onto cooler air, which may eventually drift into the rest of your home. Leaving the fan setting on will sometimes pull more cold air upward, increasing the amount of heating you need to keep warm.

If you’re still trying to decide if you should switch to the fan/on setting, remember that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on could work for you if:

Someone in your household deals with allergies. Allergies and other respiratory conditions can be stressful on the family. Leaving the fan on is more likely to increase indoor air quality, helping your family breathe easier.

Your home experiences hot and cold spots. Lots of homes wrestle with persistent hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting should help minimize these changes by consistently refreshing each room’s ventilation.